Chip package structure and method for forming the same

ABSTRACT

A method for forming a chip package structure is provided. The method includes forming a conductive via structure in a first substrate. The method includes bonding a chip to a first surface of the first substrate. The method includes forming a barrier layer over a second surface of the first substrate. The method includes forming a first insulating layer over the barrier layer. The method includes forming a conductive pad over the first insulating layer and in the first opening, the second opening, and the third opening. The conductive pad continuously extends from the conductive via structure into the third opening. The method includes forming a conductive bump over the conductive pad in the third opening.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications,such as personal computers, cell phones, digital cameras, and otherelectronic equipment. Semiconductor devices are typically fabricated bysequentially depositing insulating or insulating layers, conductivelayers, and semiconductor layers over a semiconductor substrate, andpatterning the various material layers using lithography to form circuitcomponents and elements.

Dozens or hundreds of integrated circuits are typically manufactured ona single semiconductor wafer. The individual dies are singulated bysawing the integrated circuits along scribe lines. The individual diesare then packaged separately to form packages. Each package is bonded toa substrate. During the bonding process, the bonding stress between thepackage and the substrate tends to lower the yield of the bondingprocess. Therefore, it is a challenge to improve the yield of thebonding process.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A-1H are cross-sectional views of various stages of a process forforming a chip package structure, in accordance with some embodiments.

FIG. 1E-1 is a top view of the chip package structure of FIG. 1E, inaccordance with some embodiments.

FIG. 1G-1 is a top view of the chip package structure of FIG. 1G, inaccordance with some embodiments.

FIG. 2 is a cross-sectional view illustrating a chip package structure,in accordance with some embodiments.

FIGS. 3A-3C are cross-sectional views of various stages of a process forforming a chip package structure, in accordance with some embodiments.

FIG. 4A is a cross-sectional view illustrating a chip package structure,in accordance with some embodiments.

FIG. 4B is a top view of the chip package structure of FIG. 4A, inaccordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the subject matterprovided. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as “beneath,” “below,”“lower,” “above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. It should be understoodthat additional operations can be provided before, during, and after themethod, and some of the operations described can be replaced oreliminated for other embodiments of the method.

Some embodiments of the disclosure are described. Additional operationscan be provided before, during, and/or after the stages described inthese embodiments. Some of the stages that are described can be replacedor eliminated for different embodiments. Additional features can beadded to the semiconductor device structure. Some of the featuresdescribed below can be replaced or eliminated for different embodiments.Although some embodiments are discussed with operations performed in aparticular order, these operations may be performed in another logicalorder.

FIGS. 1A-1H are cross-sectional views of various stages of a process forforming a chip package structure, in accordance with some embodiments.As shown in FIG. 1A, a substrate 110 is provided, in accordance withsome embodiments. In some embodiments, the substrate 110 is aninterposer wafer. The substrate 110 includes a semiconductor substrate111, conductive via structures 112, a barrier layer 113, and aredistribution structure 114, in accordance with some embodiments.

The semiconductor substrate 111 has surfaces 111 a and 111 b, inaccordance with some embodiments. In some embodiments, the semiconductorsubstrate 111 is made of an elementary semiconductor material includingsilicon or germanium in a single crystal, polycrystal, or amorphousstructure.

In some other embodiments, the semiconductor substrate 111 is made of acompound semiconductor (e.g., silicon carbide, gallium arsenide, galliumphosphide, indium phosphide, or indium arsenide), an alloy semiconductor(e.g., SiGe or GaAsP), or a combination thereof. The semiconductorsubstrate 111 may also include multi-layer semiconductors, semiconductoron insulator (SOI) (such as silicon on insulator or germanium oninsulator), or a combination thereof.

The conductive via structures 112 are formed in the semiconductorsubstrate 111, in accordance with some embodiments. The conductive viastructures 112 may be formed to extend from the surface 111 a into thesemiconductor substrate 111. The barrier layer 113 is formed over thesemiconductor substrate 111, in accordance with some embodiments. Thebarrier layer 113 is between the conductive via structures 112 and thesemiconductor substrate 111, in accordance with some embodiments.

The barrier layer 113 is configured to prevent the material of theconductive via structures 112 from diffusing into the semiconductorsubstrate 111, in accordance with some embodiments. The barrier layer113 is further configured to electrically insulate the conductive viastructures 112 from the semiconductor substrate 111, in accordance withsome embodiments.

The barrier layer 113 is made of a silicon-containing material such assilicon nitride, silicon oxide, silicon oxynitride, silicon carbide, thelike, or a combination thereof, in accordance with some embodiments. Insome other embodiments, the barrier layer 113 is made of phosphosilicateglass (PSG), borosilicate glass (BSG), boron-doped phosphosilicate glass(BPSG), fluorine-doped silicate glass (FSG), tetraethyl orthosilicate(TEOS), or the like.

The barrier layer 113 is formed using an oxidation process, a depositionprocess, a spin-on coating process, or another suitable process. Thedeposition process includes a chemical vapor deposition (CVD) processsuch as a flowable chemical vapor deposition (FCVD) process, a plasmaenhanced chemical vapor deposition (PECVD) process, a low pressurechemical vapor deposition (LPCVD) process, or the like, in accordancewith some embodiments.

In some embodiments, the substrate 110 is a device wafer that includesvarious device elements. In some embodiments, the various deviceelements are formed in and/or over the semiconductor substrate 111. Thedevice elements are not shown in figures for the purpose of simplicityand clarity. Examples of the various device elements include activedevices, passive devices, other suitable elements, or a combinationthereof. The active devices may include transistors or diodes (notshown) formed at the surface 111 a. The passive devices includeresistors, capacitors, or other suitable passive devices.

For example, the transistors may be metal oxide semiconductor fieldeffect transistors (MOSFET), complementary metal oxide semiconductor(CMOS) transistors, bipolar junction transistors (BJT), high-voltagetransistors, high-frequency transistors, p-channel and/or n-channelfield effect transistors (PFETs/NFETs), etc. Various processes, such asfront-end-of-line (FEOL) semiconductor fabrication processes, areperformed to form the various device elements. The FEOL semiconductorfabrication processes may include deposition, etching, implantation,photolithography, annealing, planarization, one or more other applicableprocesses, or a combination thereof.

In some embodiments, isolation features (not shown) are formed in thesemiconductor substrate 111. The isolation features are used to defineactive regions and electrically isolate various device elements formedin the active regions. In some embodiments, the isolation featuresinclude shallow trench isolation (STI) features, local oxidation ofsilicon (LOCOS) features, other suitable isolation features, or acombination thereof.

The redistribution structure 114 is formed over the semiconductorsubstrate 111, in accordance with some embodiments. The redistributionstructure 114 includes an insulating layer 114 a, wiring layers 114 b,conductive vias 114 c, and conductive pads 114 d, in accordance withsome embodiments. The insulating layer 114 a is formed over the surface111 a, in accordance with some embodiments. The wiring layers 114 b areformed in the insulating layer 114 a, in accordance with someembodiments.

As shown in FIG. 1A, the conductive vias 114 c are electricallyconnected between different wiring layers 114 b and between the wiringlayer 114 b and the conductive pads 114 d, in accordance with someembodiments. For the sake of simplicity, FIG. 1A only shows one of thewiring layers 114 b, in accordance with some embodiments.

The conductive via structures 112 are electrically connected to theconductive pads 114 d through the wiring layers 114 b and the conductivevias 114 c, in accordance with some embodiments. The conductive pads 114d are formed over the insulating layer 114 a, in accordance with someembodiments. The conductive via structures 112, the wiring layers 114 b,the conductive vias 114 c, and the conductive pads 114 d are made of aconductive material, such as copper (Cu), aluminum (Al), tungsten (W),cobalt (Co), nickel (Ni), or another suitable material, in accordancewith some embodiments.

As shown in FIG. 1A, conductive bumps 115 are respectively formed overthe conductive pads 114 d, in accordance with some embodiments. Theconductive bumps 115 are made of a conductive material, such as copper(Cu), aluminum (Al), tungsten (W), cobalt (Co), nickel (Ni), or anothersuitable material, in accordance with some embodiments. As shown in FIG.1A, solder layers 116 are respectively formed over the conductive bumps115, in accordance with some embodiments. The solder layers 116 are madeof a conductive material, such as Tin (Sn) or another suitable material,in accordance with some embodiments.

As shown in FIG. 1A, a chip 120 is provided, in accordance with someembodiments. The chip 120 includes a system on chip (SoC), in accordancewith some embodiments. The chip 120 includes various device elements, inaccordance with some embodiments. In some embodiments, the variousdevice elements are formed in the chip 120.

The device elements are not shown in figures for the purpose ofsimplicity and clarity. Examples of the various device elements includeactive devices, passive devices, other suitable elements, or acombination thereof. The active devices may include transistors ordiodes (not shown). The passive devices include resistors, capacitors,or other suitable passive devices.

For example, the transistors may be metal oxide semiconductor fieldeffect transistors (MOSFET), complementary metal oxide semiconductor(CMOS) transistors, bipolar junction transistors (BJT), high-voltagetransistors, high-frequency transistors, p-channel and/or n-channelfield effect transistors (PFETs/NFETs), etc. Various processes, such asfront-end-of-line (FEOL) semiconductor fabrication processes, areperformed to form the various device elements. The FEOL semiconductorfabrication processes may include deposition, etching, implantation,photolithography, annealing, planarization, one or more other applicableprocesses, or a combination thereof.

In some embodiments, isolation features (not shown) are formed in thechip 120. The isolation features are used to define active regions andelectrically isolate various device elements formed in the activeregions. In some embodiments, the isolation features include shallowtrench isolation (STI) features, local oxidation of silicon (LOCOS)features, other suitable isolation features, or a combination thereof.

As shown in FIG. 1A, conductive bumps 132 are formed over the chip 120,in accordance with some embodiments. As shown in FIG. 1A, solder layers134 are respectively formed over the conductive bumps 132, in accordancewith some embodiments. The solder layers 134 are made of a conductivematerial, such as Tin (Sn) or another suitable material, in accordancewith some embodiments.

As shown in FIGS. 1A and 1B, the chip 120 is disposed over the substrate110, in accordance with some embodiments. Thereafter, a reflow processis performed over the solder layers 134 and 116, in accordance with someembodiments. After the reflow process, each solder layer 134 and thesolder layer 116 thereunder melt and mix together to form a solder ball136, in accordance with some embodiments. Therefore, the chip 120 isbonded to the substrate 110 through the conductive bumps 132 and 115 andthe solder balls 136, in accordance with some embodiments.

As shown in FIG. 1B, an underfill layer 140 is formed into a gap G1between the substrate 110 and the chip 120, in accordance with someembodiments. The underfill layer 140 surrounds the conductive bumps 132and 115, the solder balls 136, and the chip 120, in accordance with someembodiments. The underfill layer 140 includes a polymer material (e.g.,a molding compound material, epoxy, or resin), in accordance with someembodiments.

As shown in FIG. 1B, a molding layer 150 is formed over the substrate110, in accordance with some embodiments. The molding layer 150surrounds the chip 120, the underfill layer 140, the conductive bumps132 and 115, and the solder balls 136, in accordance with someembodiments. The molding layer 150 includes a polymer material (e.g., amolding compound material, epoxy, or resin), in accordance with someembodiments. The formation of the molding layer 150 includes forming amolding material layer over the substrate 110, the underfill layer 140,and the chip 120; and performing a planarization process over themolding material layer to remove an upper portion of the moldingmaterial layer until a top surface 122 of the chip 120 is exposed, inaccordance with some embodiments. The top surface 122 and 152 of thechip 120 and the molding layer 150 are substantially coplanar, inaccordance with some embodiments.

As shown in FIG. 1C, a lower portion of the semiconductor substrate 111is removed, in accordance with some embodiments. The removal processincludes a chemical mechanical polishing (CMP) process, in accordancewith some embodiments. After the removal process, the conductive viastructures 112 and the barrier layer 113 are exposed, in accordance withsome embodiments.

The conductive via structures 112 and the barrier layer 113 pass throughthe semiconductor substrate 111, in accordance with some embodiments.The conductive via structures 112 are also referred to asthrough-substrate vias or through-silicon vias (TSV) when thesemiconductor substrate 111 is a silicon substrate, in accordance withsome embodiments.

As shown in FIG. 1D, the semiconductor substrate 111 is flipped upsidedown, in accordance with some embodiments. As shown in FIG. 1D, abarrier layer 117 is formed over the surface 111 b, in accordance withsome embodiments. The barrier layer 117 is configured to prevent thematerial of wiring layers subsequently formed thereon from diffusinginto the semiconductor substrate 111, in accordance with someembodiments. The barrier layer 117 is further configured to electricallyinsulate wiring layers subsequently formed thereon from thesemiconductor substrate 111, in accordance with some embodiments.

The barrier layer 117 is in direct contact with the semiconductorsubstrate 111, in accordance with some embodiments. The barrier layer117 has openings 117 a, in accordance with some embodiments. Theopenings 117 a respectively expose the conductive via structures 112thereunder, in accordance with some embodiments.

The barrier layer 117 is made of a silicon-containing material such assilicon nitride, silicon oxide, silicon oxynitride, silicon carbide, thelike, or a combination thereof, in accordance with some embodiments. Insome other embodiments, the barrier layer 117 is made of phosphosilicateglass (PSG), borosilicate glass (BSG), boron-doped phosphosilicate glass(BPSG), fluorine-doped silicate glass (FSG), tetraethyl orthosilicate(TEOS), or the like.

The barrier layer 117 is formed using an oxidation process, a depositionprocess, a spin-on coating process, or another suitable process. Thedeposition process includes a chemical vapor deposition (CVD) processsuch as a flowable chemical vapor deposition (FCVD) process, a plasmaenhanced chemical vapor deposition (PECVD) process, a low pressurechemical vapor deposition (LPCVD) process, or the like, in accordancewith some embodiments. The openings 117 a are formed using aphotolithography process and an etching process, in accordance with someembodiments.

FIG. 1E-1 is a top view of the chip package structure of FIG. 1E, inaccordance with some embodiments. FIG. 1E is a cross-sectional viewillustrating the chip package structure along a sectional line I-I′ inFIG. 1E-1, in accordance with some embodiments.

As shown in FIGS. 1E and 1E-1, an insulating layer 118 is formed overthe barrier layer 117, in accordance with some embodiments. Theinsulating layer 118 has openings 118 a and 118 b, in accordance withsome embodiments. The openings 118 a are respectively over the openings117 a, in accordance with some embodiments.

The openings 118 a respectively connect with the openings 117 athereunder, in accordance with some embodiments. The openings 118 arespectively expose the conductive via structures 112 thereunder, inaccordance with some embodiments. The openings 118 a further expose thebarrier layer 117 surrounding the conductive via structures 112, inaccordance with some embodiments.

The openings 118 b partially expose the barrier layer 117 close to theconductive via structures 112, in accordance with some embodiments. Theinsulating layer 118 is partially between the openings 118 a and 118 b,in accordance with some embodiments. The barrier layer 117 is thinnerthan the insulating layer 118, in accordance with some embodiments. Thehardness of the barrier layer 117 is greater than the hardness of theinsulating layer 118, in accordance with some embodiments.

The insulating layer 118 is made of a polymer material such as epoxy,polyimide, polybenzoxazole (PBO), solder resist (SR), ABF film, and thelike, in accordance with some embodiments. In some embodiments, theinsulating layer 118 is made of a photosensitive material and mayundergo chemical reactions when exposed to light.

In some embodiments, the barrier layer 117 and the insulating layer 118are made of different materials. The insulating layer 118 is formedusing a coating process, a lamination process, a chemical vapordeposition process, the like, or a combination thereof, in accordancewith some embodiments. The openings 118 a and 118 b are formed using aphotolithography process and an etching process, in accordance with someembodiments.

Thereafter, as shown in FIG. 1E, a seed layer 162 is formed over thebarrier layer 117, the insulating layer 118, and the conductive viastructures 112, in accordance with some embodiments. The seed layer 162conformally covers the barrier layer 117 and the insulating layer 118and the conductive via structures 112, in accordance with someembodiments.

The seed layer 162 is in direct contact with the barrier layer 117 andthe insulating layer 118 and the conductive via structures 112, inaccordance with some embodiments. The materials of the seed layer 162include titanium, copper, or the like, in accordance with someembodiments. The seed layer 162 is formed using a physical vapordeposition (PVD) process such as a sputtering process, in accordancewith some embodiments.

Thereafter, as shown in FIGS. 1E and 1E-1, a mask layer 164 is formedover the seed layer 162, in accordance with some embodiments. The masklayer 164 has openings 164 a, in accordance with some embodiments. Eachopening 164 a exposes a portion of the seed layer 162 in the openings117 a, 118 a, and 118 b, in accordance with some embodiments. The masklayer 164 is made of a polymer material such as a photoresist material,in accordance with some embodiments.

Thereafter, as shown in FIGS. 1E and 1E-1, conductive layers 166 areformed in the openings 164 a, in accordance with some embodiments. Theconductive layers 166 conformally cover the seed layer 162 exposed bythe openings 164 a, in accordance with some embodiments. The conductivelayer 166 is thicker than the seed layer 162, in accordance with someembodiments. Each conductive layer 166 is partially in the openings 117a, 118 a, and 118 b thereunder, in accordance with some embodiments.

The conductive layer 166 is made of a metal material such as copper,aluminum, nickel, tungsten, titanium, the like, or a combinationthereof, in accordance with some embodiments. The conductive layer 166is formed using an electroplating process, an electroless platingprocess, or the like, in accordance with some embodiments.

Thereafter, as shown in FIGS. 1E and 1F, the mask layer 164 is removed,in accordance with some embodiments. The removal process includes an ashprocess and/or a flush process, in accordance with some embodiments.Thereafter, as shown in FIG. 1F, the seed layer 162 originally under themask layer 164 is removed, in accordance with some embodiments. Theremoval process includes an etching process such as a wet etchingprocess or a dry etching process, in accordance with some embodiments.

As shown in FIG. 1F, after the seed layer 162 originally under the masklayer 164 is removed, each conductive layer 166 and the seed layer 162remaining under the conductive layer 166 together form a conductive pad167, in accordance with some embodiments. Each conductive pad 167continuously extends from the conductive via structure 112 (or theopening 117 a) thereunder into the opening 118 b thereunder, inaccordance with some embodiments. As shown in FIG. 1F, the conductivepad 167 has a W-like shape, in accordance with some embodiments.

Each conductive pad 167 has a first portion 167 a and a second portion167 b, in accordance with some embodiments. The first portion 167 apasses through the barrier layer 117 and the insulating layer 118 toconnect with the conductive via structure 112 thereunder, in accordancewith some embodiments. The second portion 167 b passes through theinsulating layer 118, in accordance with some embodiments.

The second portion 167 b is in direct contact with the barrier layer117, in accordance with some embodiments. The insulating layer 118 ispartially between the first portion 167 a and the second portion 167 b,in accordance with some embodiments. The insulating layer 118 separatesthe first portion 167 a from the second portion 167 b, in accordancewith some embodiments.

Thereafter, as shown in FIG. 1F, a mask layer 170 is formed over theconductive pads 167 and the insulating layer 118, in accordance withsome embodiments. The mask layer 170 is in direct contact with theconductive pads 167 and the insulating layer 118, in accordance withsome embodiments.

The mask layer 170 has openings 172 formed using suitable lithographyand etching processes, in accordance with some embodiments. Each opening172 partially exposes the conductive pad 167 (or the conductive layer166) in the opening 118 b, in accordance with some embodiments. The masklayer 170 is made of a polymer material such as a photoresist material,in accordance with some embodiments.

Thereafter, as shown in FIG. 1F, conductive bumps 180 are respectivelyformed in the openings 172, in accordance with some embodiments. Theconductive bump 180 is directly over the opening 118 b, in accordancewith some embodiments. The conductive bump 180 is directly over thesecond portion 167 b of the conductive pad 167, in accordance with someembodiments. That is, there is no seed layer between the conductive bump180 and the conductive pad 167 (or the conductive layer 166), inaccordance with some embodiments. The conductive bump 180 iselectrically connected to the conductive via structures 112 through theconductive pad 167 thereunder, in accordance with some embodiments.

The conductive bump 180 is thicker than the conductive pad 167, inaccordance with some embodiments. The conductive bump 180 is in directcontact with the conductive pad 167 (or the conductive layer 166), inaccordance with some embodiments. In some embodiments, a bottom portion182 of the conductive bump 180 is in the opening 118 b.

The conductive bump 180 and the conductive via structure 112 aremisaligned in a vertical direction V1 perpendicular to the surface 111b, in accordance with some embodiments. Therefore, during subsequentbonding processes, the bonding stress concentrated on the conductivebump 180 is not conducted to the conductive via structure 112, inaccordance with some embodiments. As a result, the conductive viastructure 112 is prevented from being damaged by the bonding stress, inaccordance with some embodiments.

The conductive bumps 180 are made of a conductive material such ascopper (Cu), aluminum (Al), tungsten (W), cobalt (Co), or nickel (Ni),in accordance with some embodiments. The conductive bumps includecontrolled collapse chip connector (C4) copper pillar bumps, inaccordance with some embodiments. The conductive bumps 180 are formedusing a plating process such as an electroplating process, in accordancewith some embodiments.

Thereafter, as shown in FIG. 1F, solder layers 190 are respectivelyformed over the conductive bumps 180, in accordance with someembodiments. The solder layers 190 are made of tin (Sn), lead-freesolder or another suitable conductive material with a melting pointlower than that of the conductive bumps 180, in accordance with someembodiments. The solder layers 190 are formed using a plating processsuch as an electroplating process, in accordance with some embodiments.

FIG. 1G-1 is a top view of the chip package structure of FIG. 1G, inaccordance with some embodiments. FIG. 1G is a cross-sectional viewillustrating the chip package structure 100 along a sectional line I-I′in FIG. 1G-1, in accordance with some embodiments. As shown in FIGS. 1Gand 1G-1, the mask layer 170 is removed, in accordance with someembodiments. The removal process includes an ash process and/or a flushprocess, in accordance with some embodiments.

Thereafter, as shown in FIGS. 1F and 1G, a reflow process is performedover the solder layers 190 to convert the solder layers 190 into solderballs 190 a, in accordance with some embodiments. As shown in FIG. 1G, acutting process is performed to cut through the substrate 110 and themolding layer 150 along predetermined scribe lines SC to form chippackage structures 100, in accordance with some embodiments. For thesake of simplicity, FIG. 1G-1 only shows one of the chip packagestructures 100.

As shown in FIG. 1G, a contact area between the conductive bump 180 andthe conductive pad 167 is greater than an area of a top surface 180 a ofthe conductive bump 180, in accordance with some embodiments. As shownin FIG. 1G-1, a width W1 of the conductive pad 167 is greater than a sumof a width W2 of the conductive bump 180, a width W3 of the conductivevia structure 112, and a distance D between the conductive bump 180 andthe conductive via structure 112, in accordance with some embodiments.

As shown in FIG. 1H, the chip package structure 100 is flipped upsidedown, in accordance with some embodiments. As shown in FIG. 1H, the chippackage structure 100 is bonded to a substrate 210 through the solderballs 190 a, in accordance with some embodiments.

During the bonding process, the bonding stress between the chip packagestructure 100 and the substrate 210 tends to concentrate on theconductive bumps 180, in accordance with some embodiments. If theconductive pad 167 under the conductive bumps 180 is entirely separatedfrom the barrier layer 117 by the insulating layer 118, the bondingstress concentrated on the conductive bumps 180 may be conducted to theinsulating layer 118 and may damage the insulating layer 118, which maylower the yield of the bonding process.

Since the conductive pads 167 under the conductive bumps 180 are indirect contact with the barrier layer 117, the bonding stressconcentrated on the conductive bumps 180 is directly conducted to thebarrier layer 117 and the semiconductor substrate 111, in accordancewith some embodiments. Therefore, the insulating layer 118 is preventedfrom being damaged by the bonding stress concentrated on the conductivebumps 180, in accordance with some embodiments. Since the barrier layer117 is harder and thinner than the insulating layer 118, the barrierlayer 117 is able to withstand the bonding stress concentrated on theconductive bumps 180, in accordance with some embodiments. As a result,the yield of the bonding process is improved, in accordance with someembodiments.

Furthermore, since the conductive bumps 180 are formed over theconductive pads 167 passing through the insulating layer 118, thecoplanarity of the conductive bumps 180 are not affected by thecoplanarity of the insulating layer 118, in accordance with someembodiments. Therefore, the coplanarity of the conductive bumps 180 areimproved, in accordance with some embodiments. As a result, the yield ofthe bonding process is improved, in accordance with some embodiments.

In some embodiments, a ratio of a width W1 of the opening 118 a to awidth W2 of the conductive bump 180 ranges from about 0.3 to about 1. Insome embodiments, the ratio of the width W1 of the opening 118 a to thewidth W2 of the conductive bump 180 ranges from about 0.3 to about 0.8.If the ratio of the width W1 of the opening 118 a to the width W2 of theconductive bump 180 is less than 0.3, the yield of the bonding processis slightly improved or not improved.

The substrate 210 includes an insulating layer 212, wiring layers 214,conductive vias 216, and pads 218, in accordance with some embodiments.The wiring layers 214 are formed in the insulating layer 212, inaccordance with some embodiments. The conductive pads 218 are formedover the insulating layer 212, in accordance with some embodiments. Theconductive vias 216 are electrically connected between different wiringlayers 214 and between the wiring layers 214 and the conductive pads218, in accordance with some embodiments.

As shown in FIG. 1H, an underfill layer 220 is formed between thesubstrates 110 and 210, in accordance with some embodiments. In someembodiments, a portion of the underfill layer 220 is formed over thesubstrate 210 and surrounds the chip package structure 100. Theunderfill layer 220 is made of an insulating material, such as a polymermaterial, in accordance with some embodiments. In this step, a chippackage structure 200 is substantially formed, in accordance with someembodiments.

FIG. 2 is a cross-sectional view illustrating a chip package structure,in accordance with some embodiments. As shown in FIG. 2, after the stepof FIG. 1F, the mask layer 170 is removed, and then an insulating layer230 is formed over the insulating layer 118 and the conductive pads 167,in accordance with some embodiments.

The insulating layer 230 covers portions of the conductive pads 167,which are not covered by the conductive bumps 180, in accordance withsome embodiments. That is, the insulating layer 230 dose not verticallyoverlap with the conductive bumps 180, in accordance with someembodiments. The insulating layer 230 surrounds the conductive bumps180, in accordance with some embodiments.

The insulating layer 230 is made of a polymer material such as epoxy,polyimide, polybenzoxazole (PBO), solder resist (SR), and the like, inaccordance with some embodiments. In some embodiments, the insulatinglayer 230 is made of a photosensitive material and may undergo chemicalreactions when exposed to light.

In some embodiments, the barrier layer 117 and the insulating layer 230are made of different materials. The insulating layer 230 is formedusing a dispensing process, a coating process, the like, or acombination thereof, in accordance with some embodiments. As shown inFIG. 2, the steps of FIGS. 1G-1H are performed to form a chip packagestructure 300, in accordance with some embodiments.

FIGS. 3A-3C are cross-sectional views of various stages of a process forforming a chip package structure, in accordance with some embodiments.As shown in FIG. 3A, after the step of FIG. 1E, the mask layer 164 isremoved, and then an insulating layer 310 is formed over the insulatinglayer 118 and the conductive pads 167, in accordance with someembodiments. The insulating layer 310 has openings 312, in accordancewith some embodiments. The openings 312 expose the conductive pads 167in the openings 118 b of the insulating layer 118, in accordance withsome embodiments.

The insulating layer 310 is made of a polymer material such as epoxy,polyimide, polybenzoxazole (PBO), solder resist (SR), and the like, inaccordance with some embodiments. In some embodiments, the insulatinglayer 310 is made of a photosensitive material and may undergo chemicalreactions when exposed to light. In some embodiments, the barrier layer117 and the insulating layer 310 are made of different materials.

The insulating layer 310 is formed using a coating process, a laminationprocess, a chemical vapor deposition process, the like, or a combinationthereof, in accordance with some embodiments. The openings 312 areformed using a photolithography process and an etching process, inaccordance with some embodiments.

As shown in FIG. 3A, a seed layer 320 is formed over the insulatinglayer 310 and the conductive pads 167, in accordance with someembodiments. In some embodiments, bottom portions 322 of the seed layer320 pass through the insulating layer 310 to conformally cover thesecond portions 167 b of the conductive pads 167.

The bottom portions 322 of the seed layer 320 are partially in theinsulating layer 118, in accordance with some embodiments. The seedlayer 320 is made of titanium, copper, or the like, in accordance withsome embodiments. The materials of the seed layer 320 may include othermetals, such as silver, gold, aluminum, and combinations thereof.

Thereafter, as shown in FIG. 3A, a mask layer 170 is formed over theseed layer 320, in accordance with some embodiments. The mask layer 170is in direct contact with the seed layer 320, in accordance with someembodiments. The mask layer 170 has openings 172, in accordance withsome embodiments. The openings 172 partially expose the seed layer 320,in accordance with some embodiments. The mask layer 170 is made of apolymer material such as a photoresist material, in accordance with someembodiments.

Thereafter, as shown in FIG. 3A, conductive bumps 180 are respectivelyformed in the openings 172, in accordance with some embodiments. Theconductive bump 180 is in direct contact with the seed layer 320, inaccordance with some embodiments. The conductive bump 180 is directlyover the opening 118 b, in accordance with some embodiments. Theconductive bump 180 is directly over the second portion 167 b of theconductive pad 167, in accordance with some embodiments.

The conductive bump 180 and the conductive via structure 112 aremisaligned in a vertical direction V1 perpendicular to the surface 111b, in accordance with some embodiments. In some embodiments, a bottomportion 184 of the conductive bump 180 passes through the insulatinglayer 310. The insulating layer 310 is partially between the conductivebump 180 and the conductive pad 167, in accordance with someembodiments.

The conductive bumps 180 are made of a conductive material such ascopper (Cu), aluminum (Al), tungsten (W), cobalt (Co), or nickel (Ni),in accordance with some embodiments. The conductive bumps 180 are formedusing a plating process such as an electroplating process, in accordancewith some embodiments.

Thereafter, as shown in FIG. 3A, solder layers 190 are respectivelyformed over the conductive bumps 180, in accordance with someembodiments. The solder layers 190 are made of tin (Sn), lead-freesolder or another suitable conductive material with a melting pointlower than that of the conductive bumps 180, in accordance with someembodiments. The solder layers 190 are formed using a plating processsuch as an electroplating process, in accordance with some embodiments.

As shown in FIG. 3B, the mask layer 170 is removed, in accordance withsome embodiments. The removal process includes an ash process and/or aflush process, in accordance with some embodiments. Thereafter, as shownin FIG. 3B, the seed layer 320 originally under the mask layer 170 isremoved, in accordance with some embodiments. The removal processincludes an etching process such as a wet etching process or a dryetching process, in accordance with some embodiments.

Thereafter, as shown in FIG. 3B, a reflow process is performed over thesolder layers 190 to convert the solder layers 190 into solder balls 190a, in accordance with some embodiments. As shown in FIG. 3B, a cuttingprocess is performed to cut through the insulating layer 310, thesubstrate 110 and the molding layer 150 along predetermined scribe linesSC to form chip package structures 400, in accordance with someembodiments.

The conductive bump 180 is electrically connected to the conductive viastructures 112 through the seed layer 320 and the conductive pad 167thereunder, in accordance with some embodiments. As shown in FIG. 3C,the step of FIG. 1H is performed to form a chip package structure 500,in accordance with some embodiments.

FIG. 4A is a cross-sectional view illustrating a chip package structure600, in accordance with some embodiments. FIG. 4B is a top view of thechip package structure 600 of FIG. 4A, in accordance with someembodiments. FIG. 4A is a cross-sectional view illustrating the chippackage structure 600 along a sectional line I-I′ in FIG. 4B, inaccordance with some embodiments.

As shown in FIGS. 4A and 4B, the chip package structure 600 is similarto the chip package structure 500 of FIG. 3C, except that the conductivebumps 180 vertically overlap the conductive via structures 112, inaccordance with some embodiments.

Processes and materials for forming the chip package structures 300, 500and 600 may be similar to, or the same as, those for forming the chippackage structure 200 described above.

In accordance with some embodiments, chip package structures and methodsfor forming the same are provided. The methods (for forming the chippackage structure) includes: sequentially forming a barrier layer and ainsulating layer over a substrate; forming a conductive pad over theinsulating layer, wherein the conductive pad has a first portion and asecond portion, the first portion passes through the barrier layer andthe second insulating to connect with a conductive via structure in thesubstrate, and the second portion passes through the insulating layer;and forming a conductive bump over the second portion. While bonding thesubstrate to another substrate through the conductive bump, the bondingstress tends to concentrate on the conductive bump. Since the secondportion passes through the insulating layer, the bonding stressconcentrated on the conductive bump is directly conducted to the barrierlayer and the substrate, not conducted to the insulating layer.Therefore, the insulating layer is protected from damage due to bondingstress. As a result, the yield of the bonding process is improved.

In accordance with some embodiments, a method for forming a chip packagestructure is provided. The method includes forming a conductive viastructure in a first substrate. The method includes bonding a chip to afirst surface of the first substrate. The method includes forming abarrier layer over a second surface of the first substrate. The barrierlayer is in direct contact with the first substrate, and the barrierlayer has a first opening exposing the conductive via structure. Themethod includes forming a first insulating layer over the barrier layer.The first insulating layer has a second opening and a third opening, thesecond opening is over the first opening and exposes the conductive viastructure, and the third opening partially exposes the barrier layer.The barrier layer is thinner than the first insulating layer. The methodincludes forming a conductive pad over the first insulating layer and inthe first opening, the second opening, and the third opening. Theconductive pad continuously extends from the conductive via structureinto the third opening. The method includes forming a conductive bumpover the conductive pad in the third opening.

In accordance with some embodiments, a method for forming a chip packagestructure is provided. The method includes forming a conductive viastructure in a substrate. The method includes bonding a chip to a firstsurface of the substrate. The method includes forming a barrier layerover a second surface of the substrate. The barrier layer is in directcontact with the substrate. The method includes forming a firstinsulating layer partially over the barrier layer. The method includesforming a conductive pad over the first insulating layer. The conductivepad has a first portion and a second portion, the first portion passesthrough the barrier layer and the first insulating layer to connect withthe conductive via structure, and the second portion passes through thefirst insulating layer and is in direct contact with the barrier layer.The method includes forming a second insulating layer over the firstinsulating layer and the conductive pad. The method includes forming aconductive bump over the second insulating layer, wherein a first bottomportion of the conductive bump passes through the second insulatinglayer to connect with the second portion of the conductive pad.

In accordance with some embodiments, a chip package structure isprovided. The chip package structure includes a first substrate. Thechip package structure includes a conductive via structure passingthrough the first substrate. The chip package structure includes a chipover a first surface of the first substrate. The chip package structureincludes a barrier layer over a second surface of the first substrate.The barrier layer is in direct contact with the first substrate. Thechip package structure includes a first insulating layer over thebarrier layer. The chip package structure includes a conductive pad overthe first insulating layer. The conductive pad has a first portion and asecond portion, the first portion passes through the barrier layer andthe first insulating layer to connect with the conductive via structure,and the second portion passes through the first insulating layer and isin direct contact with the barrier layer. The chip package structureincludes a conductive bump over the second portion of the conductivepad.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method for forming a chip package structure,comprising: forming a conductive via structure in a first substrate;bonding a chip to a first surface of the first substrate; forming abarrier layer over a second surface of the first substrate, wherein thebarrier layer is in direct contact with the first substrate, and thebarrier layer has a first opening exposing the conductive via structure;forming a first insulating layer over the barrier layer, wherein thefirst insulating layer has a second opening and a third opening, thesecond opening is over the first opening and exposes the conductive viastructure, the third opening partially exposes the barrier layer, andthe barrier layer is thinner than the first insulating layer; forming aconductive pad over the first insulating layer and in the first opening,the second opening, and the third opening, wherein the conductive padcontinuously extends from the conductive via structure into the thirdopening; and forming a conductive bump over the conductive pad in thethird opening.
 2. The method for forming the chip package structure asclaimed in claim 1, further comprising: bonding the first substrate to asecond substrate through the conductive bump.
 3. The method for formingthe chip package structure as claimed in claim 1, wherein the conductivebump is thicker than the conductive pad, and the conductive bump is indirect contact with the conductive pad.
 4. The method for forming thechip package structure as claimed in claim 1, wherein a bottom portionof the conductive bump is in the third opening.
 5. The method forforming the chip package structure as claimed in claim 1, wherein thesecond opening further exposes a portion of the barrier layer.
 6. Themethod for forming the chip package structure as claimed in claim 1,wherein the conductive bump and the conductive via structure aremisaligned in a vertical direction perpendicular to the second surface.7. The method for forming the chip package structure as claimed in claim1, further comprising: after forming the conductive bump over theconductive pad in the third opening, forming a second insulating layerover the first insulating layer and the conductive pad, wherein thesecond insulating layer surrounds the conductive bump.
 8. The method forforming the chip package structure as claimed in claim 1, wherein afirst width of the conductive pad is greater than a sum of a secondwidth of the conductive bump, a third width of the conductive viastructure, and a distance between the conductive bump and the conductivevia structure.
 9. The method for forming the chip package structure asclaimed in claim 1, wherein the forming of the conductive bumpcomprises: forming a mask layer over the conductive pad and the firstinsulating layer, wherein the mask layer is in direct contact with theconductive pad and the first insulating layer, and the mask layer has afourth opening exposing the conductive pad in the third opening; formingthe conductive bump in the fourth opening; and removing the mask layer.10. The method for forming the chip package structure as claimed inclaim 1, wherein the barrier layer and the first insulating layer aremade of different materials.
 11. A method for forming a chip packagestructure, comprising: forming a conductive via structure in asubstrate; bonding a chip to a first surface of the substrate; forming abarrier layer over a second surface of the substrate, wherein thebarrier layer is in direct contact with the substrate; forming a firstinsulating layer partially over the barrier layer; forming a conductivepad over the first insulating layer, wherein the conductive pad has afirst portion and a second portion, the first portion passes through thebarrier layer and the first insulating layer to connect with theconductive via structure, and the second portion passes through thefirst insulating layer and is in direct contact with the barrier layer;forming a second insulating layer over the first insulating layer andthe conductive pad; and forming a conductive bump over the secondinsulating layer, wherein a first bottom portion of the conductive bumppasses through the second insulating layer to connect with the secondportion of the conductive pad.
 12. The method for forming the chippackage structure as claimed in claim 11, further comprising: beforeforming the conductive bump over the second insulating layer, forming aseed layer over the second insulating layer, wherein a second bottomportion of the seed layer passes through the second insulating layer toconformally cover the second portion of the conductive pad, and theconductive bump is formed over the seed layer.
 13. The method forforming the chip package structure as claimed in claim 12, wherein thesecond bottom portion of the seed layer is partially in the firstinsulating layer.
 14. The method for forming the chip package structureas claimed in claim 11, wherein the conductive pad has a W-like shape ina cross-sectional view of the conductive pad.
 15. The method for formingthe chip package structure as claimed in claim 11, wherein the barrierlayer is harder than the first insulating layer.
 16. A chip packagestructure, comprising: a first substrate; a conductive via structurepassing through the first substrate; a chip over a first surface of thefirst substrate; a barrier layer over a second surface of the firstsubstrate, wherein the barrier layer is in direct contact with the firstsubstrate; a first insulating layer over the barrier layer; a conductivepad over the first insulating layer, wherein the conductive pad has afirst portion and a second portion, the first portion passes through thebarrier layer and the first insulating layer to connect with theconductive via structure, and the second portion passes through thefirst insulating layer and is in direct contact with the barrier layer;and a conductive bump over the second portion of the conductive pad. 17.The chip package structure as claimed in claim 16, wherein theconductive bump is thicker than the conductive pad, and the conductivebump is in direct contact with the conductive pad.
 18. The chip packagestructure as claimed in claim 17, wherein a contact area between theconductive bump and the conductive pad is greater than an area of a topsurface of the conductive bump.
 19. The chip package structure asclaimed in claim 16, further comprising: a second insulating layer overthe first insulating layer and the first portion of the conductive pad.20. The chip package structure as claimed in claim 16, furthercomprising: a second insulating layer over the first insulating layerand the conductive pad, wherein the conductive bump passes through thesecond insulating layer to connect with the conductive pad, and thesecond insulating layer is partially between the conductive bump and theconductive pad.